India's population has increased to 1.2 billion people this year, an increase equaling nearly the entire population of Brazil, with the South Asian nation on track to overtake China as the world's most populous nation by 2030.

Census commissioner C Chandramouli said India's population was now nearly equal to the combined populations of the US, Indonesia, Brazil, Japan, Bangladesh and Pakistan, Al Jazeera reported.

China has 1.34 billion people, leading to the United Nations projection of India's population outstripping China in two decades, although Chandramouli said India would analyze the census data and make its own projections.

A preliminary census has shown that India added 181 million people in the past decade, though growth actually slowed for the first time in 90 years.

The figures also indicated a continuing preference for boys over girls, despite campaigns against abortion based on sex selection and infanticide. Many Indians favor sons over daughters mostly because of the enormous expenses involved in marrying off girls, as an often elaborate dowry is demanded of a bride’s family by a groom’s family at the time of a wedding.

According to Dr A.L. Sharada of the charity Laadli, which works to raise the status of Indian girls, girls are still seen as a burden in India. "Marriage and dowry is the biggest burden for parents in India and the amount of money the parents need to shell out for a daughter's big fat wedding makes them a burden for their parents," he said, according to the Telegraph. Boys, however, are seen as future breadwinners who will stay with their families.

Although there was an improvement in the overall sex ratio to 940 females per 1,000 men, compared with 933 women for every 1,000 men in the 2001 census, the gap among children is widening, according to the Wall Street Journal.

Among children up to the age of six, the number of girls to 1,000 boys shrank to 914 girls to every 1,000 boys, a drop from 927 in 2001. The census figure notes that this is the lowest percentage of girls to boys since the country’s independence in 1947.

Although the government has banned doctors from revealing the sex of unborn children, and has carried out campaigns against abortion, the ever diminishing number of girls has experts worried about the repercussions on gender relations and violence when the children enter adolescence, according to the Wall Street Journal.

“The issue of discrimination is one that is deep rooted in the Indian society,” the WSJ quoted Ravi Verma, director of the Asia office of the International Center for Research on Women, as saying. “With fertility decline, the preference for son is becoming stronger.”

GK Pillai, India's interior minister, said: "Whatever measures that have been put in over the last 40 years has not had any impact on child sex ratio and therefore that requires a complete review."

The census also showed that the literacy rate went up to 74 percent nationwide for people aged seven and older, from about 65 percent in the last count.